Antônio Rogério Nogueira hails from the town of Vitória da Conquista, Brazil and trains in Brazilian Jiu-Jitsu under Ricardo de la Riva. Along with his brother, Nogueira trains with Black House. He claims that it is not usual for Brazilian twins to have the same first name but the twins' mother named them both after their father Antônio Amielto.

Before becoming a big star in PRIDE, Nogueira would compete in DEEP and HooknShoot events and would gain a record of 2-0, finishing both opponents in the very first round via armbar. Nogueira started training with the same team as his brother, Brazilian Top Team.

Nogueira would make his PRIDE Fighting Championships debut on 28 April 2002 at PRIDE 20 against Japanese pro wrestler/MMA fighter Yusuke Imamura and he was very successful, ending the fight in the first round with a guillotine choke in just 35 seconds.

Nogueira would fight again for PRIDE at PRIDE 24 against Guy Mezger. Neither man would push the action a whole lot as they both seemed a little tentative in the stand up. The fight would go to the judges scorecards and Nogueira would pick up the majority decision. Nogueira next fought at PRIDE 25 against Kazuhiro Nakamura, who was making his pro MMA debut. Nakamura fought very valiantly and even escaped multiple submissions but in the end the experience and skill of Nogueira proved to be too much and he would finish with an armbar in the second round.

In his next fight with PRIDE Nogueira would see a huge step up in competition for him as he was pitted against legendary fighter and crowd favourite Kazushi Sakuraba in the main event of PRIDE Shockwave 2003. The fight would prove to be an excellent back-and-forth battle which would see Nogueira utilise his excellent ground game and also get the better of Sakuraba standing and in the clinch. Late in the third, he would even bloody up Sakuraba with kicks. Nogueira would go on to take the unanimous decision and by beating such a huge star, he was now seen as a serious force to be reckoned with at 205 lbs.

Nogueira would beat Alex Stiebling in Korea, before returning to Japan to rematch Nakamura in the main event of PRIDE Bushido 4. Nogueira fought a very smart fight and took home the split decision victory. Nogueira won a unanimous decision victory at PRIDE 29 against Alistair Overeem in what was for the most part an even fight. Overeem would escape many of Nogueira's submission attempts but looked tired late in the fight and Nogueira would start to really take it to Overeem, even coming close to finishing him in the third round.

Nogueira would enter PRIDE's 2005 Middleweight Grand Prix next and was not given an easy first round opponent as he was slated to fight Dan Henderson in the opening round. Henderson fought Nogueira's twin brother Antônio Rodrigo Nogueira earlier in his career, and lost by armbar. Henderson would have the same luck against Nogueira and was submitted late in the first round by an armbar, as Nogueira continued on in the tournament. Nogueira was matched up in the quarter-finals against top Chute Boxe prospect Maurício Rua in a Brazilian Top Team/Chute Boxe clash. The first round of this fight is widely considered to be one of the better opening rounds in MMA history, with Nogueira dropping the rarely knocked down Shogun and rocking him later in the round while Shogun mounted some nice offense of his own, connecting with some diving punches to Nogueira and taking him down. The second and third rounds would belong to Rua however, as he would continue to land diving punches and knocked Nogueira down in the third. Rua would go on to take the decision and eventually would go on to win the tournament. This fight snapped Nogueira's eight fight winning streak and would be the first fight he lost in three years.

After this fight Nogueira took some time off to heal some old injuries of his and would not fight again until July 2006, where he rematched Overeem and would win a second-round TKO decision, when Overeem's corner threw in the towel after Nogueira staggered him and was continuing to land combos.

Nogueira fought in the United States for only the second time in his career at PRIDE 33 against relatively unknown Sokoudjou. However the fight would be Sokoudjou's arrival into the mainstream MMA audience, as he would land a high kick/left hook combo that knocked Nogueira out cleanly in what is considered to be one of the biggest upsets in all of MMA. PRIDE would close its doors soon after this and Nogueira would defeat Todd Gouwenberg at an HCF show before signing a contract to compete with Affliction Entertainment on their Affliction branded shows. Nogueira would fight Edwin Dewees next, knocking him out in the first round at Affliction: Banned, before defeating Moise Rimbon at a Sengoku show. Next, Nogueira was given a chance to avenge an earlier loss and would fight Vladimir Matyushenko at Affliction: Day of Reckoning and would indeed avenge it, knocking Matyushenko out late in the second round. After this Nogueira would submit Dion Staring in an MMA fight that took place in Brazil.

After Affliction closed its doors in July 2009, Nogueira would sign on to compete with the Ultimate Fighting Championship.

On 28 August 2009, Dana White had confirmed that Nogueira had signed a contract with the UFC.[4] Nogueira made his debut at UFC 106 against Luiz Cané. Nogueira made quick work of the Brazilian and dropped him with a sweeping left hook before finishing him off with punches on the mat at 1:56 of the first round.

Nogueira was scheduled to face Brandon Vera at UFC 109. However, Nogueira was forced off the card with a fractured ankle sustained while training.[5]

His next fight was scheduled to be against former UFC Light-Heavyweight Champion Forrest Griffin at UFC 114; however, Griffin pulled out of the fight due to a shoulder injury. Nogueira instead fought Jason Brilz on short notice.[6] In a controversial split decision, in which Brilz seemed to control the duration of the fight, Nogueira was declared the winner.[7]

Nogueira was expected to face Tito Ortiz on 26 March 2011 at UFC Fight Night 24.[9] However, Ortiz received a cut whilst training for his match with Nogueira and was forced to withdraw from the match. Ortiz was replaced by Phil Davis on short-notice, with just 6 weeks remaining until the fight.[10] Nogueira lost via unanimous decision (30-27, 30-27, 30-27).

Nogueira was originally scheduled to face Rich Franklin at UFC 133 on 6 August 2011, in Philadelphia.[11] However, Nogueira pulled out of the fight, citing a shoulder injury.[12]

Nogueira faced former UFC Light Heavyweight ChampionRashad Evans on 2 February 2013 at UFC 156.[17] The bout remained on the feet for a majority of its duration in a largely uneventful fight where neither fighter was able to deliver any significant offense. Nogueira won the fight via unanimous decision.[18]

Nogueira was expected to face Maurício Rua in a rematch on 15 June 2013 at UFC 161.[19] However, Nogueira pulled out of the bout in the days leading up to the event citing a back injury.[20]Chael Sonnen was briefly linked as a replacement for Nogueira.[21] Though an alleged visa issue created a problem for Sonnen to get into Canada, resulting in Rua being pulled from the event altogether.[22]

At a post-fight press conference in Manchester, Dana White said that Nogueira would be facing Alexander Gustafsson on 8 March 2014 at a UFC event in London.[23] However just 5 days later Nogueira was forced out of the bout due to a lingering back injury.[24] Later, reports came that said that Nogueira had never agreed to take the fight against Gustafsson at all.[25]

Ten years after their first fight, Nogueira had a rematch with Maurício Rua on 1 August 2015 at UFC 190.[29] He lost the fight again by unanimous decision. Both participants were awarded Fight of the Night honors.[30][31]

A pairing with Alexander Gustafsson was scheduled for a third time and was expected to take place on 19 November 2016 at UFC Fight Night 100.[34] However just days after the fight was announced, Gustafsson pulled out of the bout citing an injury. In turn, he was replaced by Ryan Bader.[35] Nogueira lost the one-sided fight via TKO in the third round.[36]